• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.2A
• /
• pp.97-108
• /
• 2012

Dynamic responses were measured using long-term monitoring system for Uldolmok tidal current pilot power plant which is one of jacket-type offshore structures. Among the dynamic quantities, the tilt angle was chosen because the low frequency response components can be precisely measured by dynamic tiltmeter, and the natural frequencies and modal damping ratio were successfully identified using proposed LS-FDD (least squared frequency domain decomposition) method. And the effects of tidal height and tidal current velocity on the variation of natural frequencies and modal damping ratios were investigated in time and frequency domain. Also the non-parametric models were tested to model the relationship between tidal conditions and modal properties such as natural frequencies and damping ratios.

• Journal of Ginseng Research
• /
• v.34 no.4
• /
• pp.304-313
• /
• 2010

This study was undertaken to discover the effects and possible mechanisms of the effect of red ginseng extract (RGE) on spontaneous sleep. The effects of a low dose (10 mg/kg) and a high dose (200 mg/kg) of RGE were compared in rats. After recovery from a surgical operation enabling electroencephalograms recordings, rats were administered RGE orally. RGE was administered orally for 1 day or once per day for 5 days in either 10 or 200 mg/kg doses. Polygraphic signs were recorded for 12 h after oral administration of RGE. Both treatment with a large dose (200 mg/kg) of RGE for one day and treatment with either a large or a small dose for 5 days reduced the number of sleep.wake cycles. Daily treatment with RGE (either 10 or 200 mg/kg) for 5 days augmented NREM and total sleep, but reduced wakefulness. Delta wave activity recorded during non-REM (NREM) sleep and REM sleep was increased after one treatment with RGE (either 10 or 200 mg/kg). Delta wave activity during NREM was enhanced after daily treatment with RGE (either 10 or 200 mg/kg) for 5 days. Both alpha and beta subunits of the $\gamma$-aminobutyric acid $(GABA)_A$ receptor were significantly over-expressed in the hypothalamus of the RGE-treated groups. Moreover, the expression of glutamic acid decarboxylase was also increased in the hypothalamus. These results demonstrate that RGE may regulate spontaneous sleep via $GABA_A$ergic systems.

• Clinical and Experimental Pediatrics
• /
• v.55 no.12
• /
• pp.481-486
• /
• 2012

Purpose: Precocious puberty is defined as breast development before the age of 8 years in girls. The present study aimed to reveal the diagnosis of Korean girls referred for precocious puberty and to compare the constitutional and endocrinological features among diagnosis groups. Methods: The present study used a retrospective chart review of 988 Korean girls who had visited a pediatric endocrinology clinic from 2006 to 2010 for the evaluation of precocious puberty. Study groups comprised fast puberty, true precocious puberty (PP), pseudo PP, premature thelarche, and control. We determined the height standard deviation score (HSDS), weight standard deviation score (WSDS), and body mass index standard deviation score (BMISDS) of each group using the published 2007 Korean growth charts. Hormone tests were performed at our outpatient clinic. Results: The PP groups comprised fast puberty (67%), premature thelarche (17%), true PP (15%), and pseudo PP (1%). Advanced bone age and levels of estradiol, basal luteinizing hormone (LH), and peak LH after gonadotropin-releasing hormone stimulation testing were significantly high in the fast puberty and true PP groups compared with the control group. HSDS, WSDS, and BMISDS were significantly higher in the true PP group than in the control group (P<0.05). Conclusion: The frequent causes of PP were found to be fast puberty, true PP, and premature thelarche. Furthermore, BMISDS were significantly elevated in the true PP group. Therefore, we emphasize the need for regular follow-up of girls who are heavier or taller than others in the same age group.

• Archives of Pharmacal Research
• /
• v.29 no.8
• /
• pp.617-623
• /
• 2006

In our ongoing search for bioactive compounds originating from the endemic species in Korea, we found that the hexane and EtOAc fractions of the MeOH extract from the root of Dystaenia takeshimana (Nakai) Kitagawa (Umbelliferae) showed cyclooxygenase-2 (COX-2) and 5- lipoxygenase (5-LOX) dual inhibitory activity by assessing their effects on the production of prostaglandin $D_2\;(PGD_2)$ and leukotriene $C_4\;(LTC_4)$ in mouse bone marrow-derived mast cells. By activity-guided fractionation, five coumarins, viz. psoralen (2), xanthotoxin (3), scopoletin (4), umbelliferone (5), and (+)-marmesin (6), together with ${\beta}-sitosterol$ (1), were isolated from the hexane fraction, and two phenethyl alcohol derivatives, viz. 2-methoxy-2-(4'-hydroxyphenyl)ethanol (7) and 2-hydroxy-2-(4'-hydroxyphenyl)ethanol (8), three flavonoids, viz. apigenin (9), luteolin (10), and cynaroside (11), as well as daucosterol (12) were isolated from the EtOAc fraction using silica gel column chromatography. In addition, D-mannitol (13) was isolated from the BuOH fraction by recrystallization. Two of the coumarins, scopoletin (4) and (+)- marmesin (6), the two phenethyl alcohol derivatives (7, 8) and the three flavonoids (9-11) were isolated for the first time from this plant. Among the compounds isolated from this plant, the five coumarins as well as the three flavonoids showed COX-2/5-LOX dual inhibitory activity. These results suggest that the anti-inflammatory activity of D. takeshimana might in part occur via the inhibition of the generation of eicosanoids.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2003.05a
• /
• pp.289-293
• /
• 2003

This study dealt with the characterization of $MoSi_2$ based composites containing three types of additive materials such as SiC, $NbSi_2\;and\;ZrO_2$ particles have been investigated, based on the detailed examination of their microstructures and fracture surfaces. The effects of reinforcing materials on the high temperature strength of $MoSi_2$ based composites have been also examined. $MoSi_2$ based composites were fabricated by the hot press process under the vacuum atmosphere. The volume fraction of reinforcing materials in the composite system was fixed as 20 %. The microstructures and the mechanical properties of $MoSi_2$ based composites were investigated by means of SEM, EDS, XRD and three point bending test.

• Restorative Dentistry and Endodontics
• /
• v.28 no.6
• /
• pp.449-456
• /
• 2003

The purpose of this study is to evaluate the sealing effect of several root-end filling materials using spectrophotometric analysis. 180 single root teeth with one canal were instrumented and canal filled. Root resected and root end preparation was made. Teeth were randomly classified to S experimental group(MTA, EBA, IRM, TCP, ZOE) and 1 control group according to root-end filling material MTA group used PRO ROOT MT A, EBA group used Super EBA. TCP group used NEW APATITE LINER TYPE II main component of which is ${\alpha}-tricalcium$ phosphate (TCP). According to manufacture's instruction experimental material was mixed and retrfilled. After 2% methylene blue solution penetration absorbance for each test sample was measured with spectrophotometer (JASCO UV-530, Japan). The mean absorbance of control and experimental group was as follows; MTA: 0.092, IRM: 0.226, Super EBA: 0.255, ZOE: 0.374, Control: 0.425, TCP: 0.501 and the result analyzed by Turkey test at P=0.05 level. Conclusions of this study are as follows; 1. The absorbance increase in following sequence MTA, IRM, Super EBA, ZOE, Control. TCP. 2. MTA showed the least leakage but was not significant with IRM or Super EBA and was significant with control or TCP(p<0.05). 3. TCP had the most leakage and was not significant with control group.

• Korean Journal of Family Medicine
• /
• v.39 no.6
• /
• pp.347-354
• /
• 2018

Background: BMI alone may not serve as an index of obesity because it does not reflect body composition. The present study aimed to compare arterial stiffness as assessed by the brachial-ankle pulse wave velocity (ba-PWV) among groups defined by body fat percentage (pBF) and BMI. Methods: This cross-sectional study was based on 1,700 participants (1,044 men and 656 women) who completed a health screening examination at a national hospital between January 2011 and February 2016. Participants were divided into four groups according to BMI and pBF: normal fat and normal weight (NFNW); excessive fat and normal weight (EFNW); normal fat and obese (NFO); and excessive fat and obese (EFO). The ba-PWV and other cardiometabolic factors were compared among the four groups in men and women separately. Results: For both sexes, the NFNW group had a lower metabolic risk compared to that in the other groups (EFNW, NFO, and EFO). After adjusting for multiple variables, the NFO males had a significantly lower ba-PWV compared to those in the other groups, including NFNW males. The NFO group had significantly more skeletal muscle mass and muscle mass compared the other groups (P<0.05). Among women, the NFNW group had a significantly lower ba-PWV compared the other groups, even after adjusting for multiple variables. Conclusion: Lower pBF in obese men may be associated with improved cardiovascular risk.

• Anatomy and Cell Biology
• /
• v.57 no.1
• /
• pp.25-30
• /
• 2024

The aim of this study was to identify the anatomical feature of retaining ligament and fat compartment on the lower eyelid and infraorbital region using a histological method, and to investigate clear definitions for them which could be used generally in the clinical area. Eighteen specimens from eight fresh Korean cadavers were stained with Masson trichrome or hematoxylin and eosin. The ligamentous and fascial fibrous tissue were clearly identified. The ligamentous fibrous tissue which traversed in the superficial and deep fat layer was skin ligament and orbicularis retaining ligament (ORL). The fascial fibrous tissue enclosed the orbicularis oculi muscle (OOc) and circumferencial adipose tissue. Based on the ligamentous and fascial structure, three fat compartments, septal, suborbicularis oculi and infraorbital fat compartment, could be identified. The OOc attached to orbital rim and dermis by ORL and skin ligament, and the muscle fascicle and fat fascicle provided the connection point to the ORL and skin ligament as enclosing all muscle and fat tissue. The combination of the force made by the skin ligament in the lower eyelid and ORL may decide the level and form of the infraorbital grooves.

• The Korean Journal of Physiology and Pharmacology
• /
• v.18 no.5
• /
• pp.425-430
• /
• 2014

This study was designed to examine the effects of histamine on gastric motility and its specific receptor in the circular smooth muscle of the human gastric corpus. Histamine mainly produced tonic relaxation in a concentration-dependent and reversible manner, although histamine enhanced contractility in a minor portion of tissues tested. Histamine-induced tonic relaxation was nerve-insensitive because pretreatment with nerve blockers cocktail (NBC) did not inhibit relaxation. Additionally, $K^+$ channel blockers, such as tetraethylammonium (TEA), apamin (APA), and glibenclamide (Glib), had no effect. However, $N^G$-nitro-L-arginine methyl ester (L-NAME) and 1H-(1,2,4)oxadiazolo (4,3-A) quinoxalin-1-one (ODQ), an inhibitor of soluble guanylate cyclase (sGC), did inhibit histamine-induced tonic relaxation. In particular, histamine-induced tonic relaxation was converted to tonic contraction by pretreatment with L-NAME. Ranitidine, the $H_2$ receptor blocker, inhibited histamine-induced tonic relaxation. These findings suggest that histamine produced relaxation in circular smooth muscle of human gastric smooth muscle through $H_2$ receptor and NO/sGC pathways.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.30 no.2
• /
• pp.14-27
• /
• 2012

This study aimed to discover new types of landscape resources that have not designated as cultural heritages through a survey of the nationwide traditional industrial landscape resources whose original forms have been lost or damaged in the aspect of management and conservation. It also discovered and analyzed the values of the traditional industrial landscape considered to be humanistic and cultural values. Among the traditional industrial landscape resources distributed nationwide, this study mainly investigated Daranginon, Dok-sal(Korean traditional stone fishing weir) and saltern. Make a list of traditional industrial landscape based on the scenic resources and analyzed the value as scenic spot by conducted basic research and field work. In case some resources were highly valued, this study aimed to rediscover the value as a cultural heritage of the traditional industrial landscape that was a basis of our ancestors' lives and has represented our traditional agricultural and fishing activities done by them over a long period of time by exploring the possibilities of being designated as cultural heritages. Continuous discoveries and studies of traditional industrial landscapes, conservation and usage of traditional industrial landscapes by being designated as a cultural heritage required to be done will be required to be done. Also, this study was supposed to be used as a basic data.